1. Field of the Invention
The present invention relates to a resistance exercise device and, more particularly, to a bar having a pair of handgrips slidably mounted thereon, the bar being adapted to be attached to a resistive force such as weights.
2. Prior Art
Resistance exercise devices are well represented in the art. Perhaps the most common such device is the barbell in which weights are removably attached to opposing ends of an elongate bar. An exercisor grips the bar with both hands and moves the bar and weights through a range of motion against the force of gravity. In most such barbell devices, the handgrips are a knurled or textured portion on the outer surface of the bar and necessarily remain stationary with respect to the bar throughout the movement (repetition). Brasher, in U.S. Pat. No. 4,585,229, discloses an exercising apparatus including a bar having a pair of rings slidably connected thereto. Handgrips for gripping by the hand of the user are positioned within, and rotatably connected to, each of the rings. A cable connects the two rings to one another for maintaining each ring at an equal distance from the end of the bar. The assembly permits the handgrips to both rotate and move laterally during a repetition. A disadvantage of the Brasher device is that the oval bar employed to mount the cable-supporting pulleys upon has a high profile and does not have the familiar appearance and feel of a conventional (stationary handgrips) barbell wherein the bar is not oval but substantially cylindrical.
Dibrowski, in U.S. Pat. No. 4,978,122 discloses a barbell wherein the handgrips are concentrically and slidably mounted on a bar and are free to rotate and slide axially. The axial motion of the handgrips is constrained by laterally disposed springs concentrically mounted on the bar, and by medially disposed stops. The springs are connected to the lateral ends of the handgrips and to the weight bar. The springs are passive centering devices that serve to generally maintain the handgrips equidistant from the center of the bar. In the event the bar tilts during a lift, the lower spring will extend and the higher spring will compress. There is no constraining interconnection of the handgrips to maintain their axial position on the bar equidistant from the center of the bar. Accordingly, due to the compressibility and extensibility of the springs, the Dibrowski device may become unbalanced when the handgrips are not equidistant from the center of gravity of the weighted bar as, for example, when the bar is tilted.
Another barbell-type resistance exercise device wherein the bar includes slidably mounted handgrips is disclosed by Troutman in U.S. Pat. No. 5,152,731. While the Troutman device permits the position of the handgrips to shift in an axial direction during a repetition, as with Dibowski, the handgrips are not interconnected to keep the handgrips equidistant from the center of gravity of the bar. Each grip includes a number of bearings that allow the grip to slide along the bar without resistance. The grips and bar include complementary anti-rotation apparatus that prevents the grips from rotating about the longitudinal axis of the bar. A number of adjustable stop members may also be placed on the bar to limit the axial travel of the grips. It is common for one arm of an exerciser to be stronger (or more fatigued) than the other. As a result, when an exerciser lifts the bar, one hand will lag relative to the other hand during the lift, tilting the bar from the horizontal. While a slight tilt is normally not a problem, with the Troutman device the bar will slide sideways through the handgrips in the direction of the lower hand. This, in turn, shifts more weight over the more fatigued or weaker arm, causing it to drop further and with weight shifted off of the stronger arm, it will rise faster causing a rapidly increasing tilt in the bar. The result is that the Troutman bar can quickly slide to one side causing the lower arm to collapse, cause muscle strain, or even cause the exerciser to fall off of the bench.
Surprisingly, a bar for a resistance-type exercise device combining the most desirable features of prior art exercise bars to overcome the limitations of each has not been suggested or disclosed in the art. There remains a need for a bar having non-rotatable, slidably mounted handgrips for use with an exercise device wherein the bar has a low profile and remains balanced throughout the range of motion of an exercisor.